Wireless

摘要

The National Transportation Safety Board warned against the potential risks to public safety of allowingnWi-Fi use of the 5850-5925 MHz band on a secondary basis, because the spectrum is set aside forna national vehicle-to-vehicle warning system. Last week, the automotive industry also opposed the proposalnunveiled in January by former FCC Chairman Julius Genachowski at CES (CD May 31 p4). “Thenimplementation of this technological opportunity to improve transportation safety so significantly mustnnot be compromised by issues associated with interference on the 5 GHz band,” the NTSB said (http:/bit.ly/ZLt3KH). “The NTSB is not opposed to spectrum sharing in principle, but the security of preestablishedncommunication frequencies related to transportation safety must first be ensured. Spectrum sharingncould put the frequencies at risk of dangerous interference, and much is still unknown about frequency interferencenwhen it comes to vast numbers of connected vehicles in motion.” NTSB has advocated intelligentnvehicle technologies “since the mid-1990s,” the filing said. “The NTSB first addressed collisionnavoidance during its investigation of a 1995 multivehicle collision in Menifee, Arkansas, in which a commercialnvehicle entered dense fog, slowed from 65 mph to between 35 and 40 mph, and was then strucknfrom behind. Subsequent collisions occurred as vehicles drove into the wreckage. ... Even then, beforentoday’s wirelessly connected world existed, the need to establish dedicated communication airwaves forntechnologies that could prevent such collisions was recognized."